I am running natively on a T40 (tried VMWare on my T42 but cannot resolve the PAE issue), and the install was pretty easy. I am not dual booting (yet at least, I have a partition reserved for XP) so when I installed I partitioned the drive which freshly erased it, then mounted the partitioin I wanted OS X on. Install was reasonably straight forward after that. Make sure when you get to the packages screen you hit "customize", then deselect:- SATA drivers- AMD- SSE3- any printer drivers you don't want

That may be the issue.

I think i have the wrong DVD, i've got: osx86_10.4.5_amd-intel_sse2-3.iso